With the development of information processing technologies, display devices such as Liquid Crystal Displays (LCDs), Plasma Display Panels (PDPs), and Active-Matrix Organic Light-Emitting Diodes (AMOLEDs) are being widely used. LCDs among these display devices require a backlight unit capable of generating light to display images.
Also, with the trend of large-sizing and large screen of display devices, a backlight unit needs to emit light having high brightness and brightness uniformity.